What is Laryngopharyngeal Reflux?

The term Laryngopharyngeal Reflux, and particularly its abbreviation – LPR – are becoming quite common. Thanks in part to the ubiquity of websites devoted to topics of health and medicine, what was an obscure diagnosis not so long ago, is now a condition that more of the general public is aware of. Having said that, an exact and agreed definition of LPR seems harder to come by, so in this post, we’ll explore what exactly LPR is (and a little bit of what it isn’t).

The most common definition of Laryngopharyngeal Reflux

At the time of writing this post, the Wikipedia article on Laryngopharyngeal Reflux states:

Laryngopharyngeal reflux (LPR), also extraesophageal reflux disease (EERD), refers to retrograde flow of gastric contents to the upper aero-digestive tract, which causes a variety of symptoms, such as cough, hoarseness, and wheezing, among others.

As the name implies, LPR is a type of reflux that affects the larynx and the pharynx which are both part of the throat, and play a role in respiration and speech. In other words, in the simplest terms, LPR is reflux that reaches the throat.

Anatomical drawing courtesy of Wikipedia

What is Reflux?

Now reflux in itself is a term worth digging into and is actually shorthand for the much more common and accepted medical diagnosis of Gastroesophageal Reflux Disease (GERD). GERD is typically associated with the symptom of heartburn and is also commonly called Acid Reflux. Some define Laryngopharyngeal Reflux as a sub-type of GERD, whereas others treat it as a separate condition.

Gastroesophageal reflux disease (GERD), also known as acid reflux, is a long-term condition where stomach contents come back up into the esophagus resulting in either symptoms or complications

Chris Kresser often refers to GERD as a disease of “acid in the wrong place at the wrong time” which is a nice way to summarise the problem. Reflux is essentially a case of stomach contents getting out of the stomach and into other parts of the body where they cause damage and discomfort.

Is LPR just a version of GERD?

On first glance, it may seem quite simple – LPR is just a version of GERD where stomach contents, and acid particularly, travel past the oesophagus all the way up into the throat and cause pain and discomfort. Unfortunately when you dig in to the topic, it quickly becomes clear that it’s much more complicated than that.

The first problem with this simplification of LPR is that many people who experience LPR, show no traditional symptoms of GERD. They feel throat discomfort and some of the associated symptoms, but none of the traditional heartburn. It may seem odd that stomach acid could travel up through the oesophagus to the throat and cause discomfort there without causing any on the way, and some medical professionals seem to believe that there is more at play than simply stomach acid reflux.

Other potential mechanisms to explain LPR

One potential explanation for the existence of LPR in the absence of traditional GERD symptoms is that the substance causing the symptoms is not stomach acid. One potential theory is that it is actually refluxed bile rather than acid that causes the symptoms of Laryngopharyngeal Reflux. This could potentially explain why sufferers don’t experience the chest pain typically associated with Acid Reflux.

Another potential theory about the cause of LPR is that it has to do with Pepsin, an enzyme that helps to digest protein in the stomach. Pepsin is activated by stomach acid, although it is not an acid itself, which may explain why LPR seems connected with Acid Reflux and yet distinct. The theory here is that Pepsin can get lodged in the throat and then can be activated by small amounts of acid, that aren’t sufficient to cause traditional heartburn, but will cause the Pepsin to damage the throat lining.

Is Laryngopharyngeal Reflux just a collection of symptoms?

With lots of different theories of what causes LPR and no consensus on which one(s) are the main driver(s), one might conclude that LPR is actually just a collection of symptoms that can’t be explained via other better understood mechanisms. These symptoms include:

Sore throat

Globus (a feeling of a lump in the throat)

Postnasal drip

Sinus congestion

Hoarseness

Cough

Loss of voice

Difficulty swallowing

Dyspesia (indigestion)

Trouble breathing

Accumulation of throat mucus

In short, LPR is characterised by symptoms of indigestion accompanied by symptoms associated with the throat and airways. It could well be that these are attributable to one or more of the causes mentioned above (acid, bile or pepsin) but it could be that there are other mechanisms at play that we’re not yet aware of.

Why does it matter?

This question of definition may not seem so important on first glance, until you realise that how one defines LPR bears a large impact on how one might go about treating it. For instance, if one defines LPR as just a particular type of GERD, one might be inclined to recommend typical GERD treatments to address it, but as we’ll explore in future posts, there’s plenty of evidence that some effective GERD treatments are much less effective for LPR.

Sadly, the jury still seems to be out on what exactly is going on in the bodies of sufferers of LPR, but thankfully more and more medical professionals are investigating this question, and hopefully clearer answers will come to light in the future.